Hermetic type compressor

ABSTRACT

A hermetic type compressor is provided in which suction port is offset arranged in the rotating direction side of rotor from the upstream of suction port with respect to the flow of the cooling medium at the front of suction port with respect to opening of suction tube, so that low-temperature cooling medium is supplied from the upstream of suction port with respect to the flow of the cooling medium at the front of suction port, the low-temperature cooling medium is efficiently suctioned from suction port, and the low-temperature cooling medium is supplied to cylinder.

TECHNICAL FIELD

The present invention relates to a hermetic type compressor used in a refrigerator.

BACKGROUND ART

Conventionally, the hermetic type compressor aimed for high efficiency includes one in which a suction port of a suction muffler faces a suction tube in proximity thereto (see e.g., patent document 1).

The conventional hermetic type compressor will now be described with reference to the drawings.

FIG. 4 is a cross sectional view of a conventional hermetic type compressor disclosed in patent document 1. FIG. 5 is a schematic view showing a main part seen in the shaft center direction of an opening of the conventional hermetic type compressor disclosed in patent document 1.

In FIGS. 4 and 5, electrically operated element 4 accommodated in sealed container 1 and configured by stator 2 and rotor 3, compression element 5 driven by electrically operated element 4, and suction tube 7 communicating with the inside and the outside of sealed container 1 and having opening 6 opening to the inside of sealed container 1 are arranged, where compression element 5 includes shaft 8 that rotates with rotor 3, cylinder 10 forming compression chamber 9, and suction muffler 12 forming sound deadening space 11 communicating with cylinder 10, and suction port 13 linking sound deadening space 11 and the space in sealed container 1 to communicate with each other is formed in suction muffler 12 and arranged so that the shaft center of suction port 13 and the shaft center of opening 6 coincide.

The operation of the hermetic type compressor configured as above will now be described.

When stator 2 is conducted and shaft 8 rotates with rotor 3, the cooling medium flowing from an external refrigeration system (not shown) is once released into sealed container 1 from opening 6 via suction tube 7, passed through suction port 13, suctioned into suction muffler 12, passed through noise deadening space 11, and taken into cylinder 10.

However, in the conventional configuration, the cooling medium in sealed container 1 rotates in the same direction as the rotation of rotor 3, and the low-temperature cooling medium released from opening 6 into sealed container 1 flows in the rotating direction of rotor 3. Thus, the cooling medium taken into suction muffler 12 through suction port 13 takes in the high-temperature cooling medium in sealed container 1 at high rates, whereby the intake quantity (cooling medium circulating amount) per unit time of the cooling medium reduces and a sufficient efficiency enhancement effect cannot be obtained.

[Patent document 1] U.S. Pat. No. 5,496,156

DISCLOSURE OF THE INVENTION

The present invention aims to provide a hermetic type compressor having a large cooling medium circulating amount and having high efficiency.

The hermetic type compressor according to the present invention has a suction port of a suction muffler offset arranged in the rotating direction of a rotor with respect to an opening of a suction tube, so that low-temperature cooling medium flows in from the upstream side with respect to the flow of the cooling medium at the front of the suction port, thereby obtaining the effect of increasing the cooling medium circulating amount by increasing the mixing rate of the low-temperature cooling medium.

The hermetic type compressor according to the present invention is a hermetic type compressor in which the cooling medium circulating amount is increased and thus the volumetric efficiency is increased, and therefore a hermetic type compressor having high efficiency can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan cross sectional view of a hermetic type compressor according to a first embodiment of the present invention.

FIG. 2 is a projection view seen from a shaft center direction of an opening of the hermetic type compressor according to the first embodiment of the present invention.

FIG. 3 is a relational view of the offset position of a suction port and refrigerating performance of the hermetic type compressor according to the first embodiment of the present invention.

FIG. 4 is a cross sectional view of a conventional hermetic type compressor.

FIG. 5 is a schematic view of the main part seen in the shaft center direction of an opening of the conventional hermetic type compressor.

PREFERRED EMBODIMENTS FOR CARRYING OUT OF THE INVENTION

Embodiments of the present invention will now be described with reference to the drawings. It should be noted that the present invention is not limited by the embodiments.

First Embodiment

FIG. 1 is a plan cross sectional view of a hermetic type compressor according to a first embodiment of the present invention. FIG. 2 is a projection view seen from a shaft center direction of an opening of the hermetic type compressor according to the first embodiment of the present invention.

In FIGS. 1 and 2, suction tube 101 is fixed to sealed container 103 at opening 102 and is opened to the inside of sealed container 103, and the other end is connected to the low pressure side of an external refrigeration system (not shown).

Electrically operated element 106 including stator 104 connected to an inverter control device (not shown) and rotor 105, and compression element 107 driven by electrically operated element 106 are accommodated in sealed container 103. Electrically operated element 106 is operated at a plurality of rotation numbers. Sealed container 103 is filled with cooling medium.

Compression element 107 is elastically supported by a plurality of coil springs 108 and includes shaft 109 fixed to rotor 105, cylinder 111 forming compression chamber 110, and suction muffler 113 forming noise deadening space 112.

Suction tube 101 having one end communicating with the refrigeration system (not shown) and the other end formed with opening 102 that opens to the inside of sealed container 103 is fixed to sealed container 103.

Noise deadening space 112 of suction muffler 113 communicates with cylinder 111. Suction port 114 communicating with noise deadening space 112 and the space inside sealed container 103 is formed on the surface of outer wall surface 115 on the sealed container side of suction muffler 113 so as to open towards the inner side of sealed container 103.

Suction port 114 is in the vicinity of opening 102 of suction tube 101. The center of suction port 114 is arranged at a position shifted in the rotating direction side of rotor 105 with respect to the center of opening 102 when seen in the shaft center direction of opening 102 of suction tube 101 (this arrangement is hereinafter referred to as “offset arrangement”). Now rotor 105 rotates clockwise from the top in FIG. 2. Furthermore, the opening area of opening 102 is larger than the opening area of suction port 114, as shown in FIG. 2. Opening 102 and suction port 114 are arranged so as to at least partially overlap with each other when seen in the shaft center direction of opening 102. Wall part 116 projecting towards the inner surface of sealed container 103 is arranged on the side surface in the rotating direction of rotor 105 of suction muffler 113.

The operation and effect of the compressor configured as above will now be described.

Stator 104 of electrically operated element 106 is conducted by an inverter control board (not shown), and rotor 105 and shaft 109 rotate. Through such operation, the pressure inside sealed container 103 lowers as the pressure inside cylinder 111 lowers during the suction stroke. As a result, the cooling medium flows from the refrigeration system (not shown) into sealed container 103 through opening 102 of suction tube 101. The cooling medium is suctioned into suction muffler 113 from suction port 114, passed through noise deadening space 112 and compressed in cylinder 111, and again discharged to the refrigeration system (not shown).

In this case, the cooling medium in sealed container 103 rotates in the same direction as the rotation of rotor 105. Furthermore, the cooling medium released into sealed container 103 from opening 102 mixes with the cooling medium in sealed container 103 while being flowed by the cooling medium in sealed container 103.

Normally, the cooling medium returned from the refrigerating cycle (not shown) has a temperature close to outside air temperature, and the cooling medium that has reached opening 102 of suction tube 101 substantially maintains such low temperature. The cooling medium in sealed. container 103, on the other hand, is exposed to compression element 107 and electrically operated element 106 of high temperature, and thus has a significantly higher temperature than the outside air temperature. The temperature of the cooling medium released into sealed container 103 from opening 102 thus rises while being flowed by the cooling medium in sealed container 103.

In the first embodiment, the low-temperature cooling medium of opening 102 is released into sealed container 103 from the upstream of suction port 114 with respect to the flow of the cooling medium at the front of suction port 114, since suction port 114 is close to opening 102 of suction tube 101 and is offset arranged in the rotating direction side of rotor 105. Therefore, the low-temperature cooling medium that has flowed thereto is efficiently suctioned from suction port 114, thereby reducing the rate at which the high-temperature cooling medium in sealed container 103 is suctioned. As a result, the low-temperature cooling medium is efficiently supplied to cylinder 111, and the refrigerating performance of the hermetic type compressor enhances. The hermetic type compressor with high efficiency is thereby achieved by enhancing the volumetric efficiency of the hermetic type compressor.

FIG. 3 is a relational view of the offset position of the suction port and the refrigerating performance of the hermetic type compressor according to the first embodiment of the present invention. As shown in FIG. 3, the refrigerating performance is at a peak as the position of suction port 114 is gradually spaced apart in the counter-rotating direction side from the rotating direction side of rotor 105 with respect to opening 102 of suction tube 101 (the spaced apart position is referred to as “offset position”). The peak is found to be at the position spaced apart in the counter-rotating direction side of rotor 105.

The refrigerating performance drastically drops when the position of suction port 114 is greatly offset arranged in the rotating direction side of rotor 105 with respect to opening 102 of suction tube 101. This is because most of the low-temperature cooling medium is flowed without being suctioned from suction port 114 when opening 102 is arranged on the downstream side with respect to the flow of the cooling medium at the front of suction port 114.

The refrigerating performance drops when the suction port is greatly offset arranged in the counter-rotating direction side of rotor 105. This is because the low-temperature cooling medium mixes with the high-temperature cooling medium before reaching the front of suction port 114 and the temperature rises, since the opening is greatly spaced apart to the upstream side with respect to the flow of the cooling medium at the front of suction port 114.

Furthermore, in FIG. 3, the offset position of opening 102 where the refrigerating performance enhances the most does not greatly change even when the rotation number of shaft 109 by inverter control is changed.

The flow of cooling medium released into sealed container 103 from opening 102 depends on the flow of the cooling medium in sealed container 103. Therefore, when operating at a plurality of rotation numbers by inverter control, the flow of the cooling medium at the front of suction port 114 greatly differs at maximum rotation number operation and at minimum rotation number operation of rotor 105. However, although the flow of the cooling medium at the front of suction port 114 is fast at the time of high rotation number operation, the speed of the cooling medium returning from the refrigerating cycle (not shown) also becomes fast because the circulating amount of cooling medium is large. The flow of the cooling medium at the front of suction port 114 is slow at the time of low rotation number operation, but the speed of the cooling medium returning from the refrigerating cycle (not shown) also becomes slow because the circulating amount of cooling medium is small. Therefore, the offset position of opening 102 at which the refrigerating performance enhances the most is estimated to be substantially constant.

As compression element 107 is elastically supported by coil spring 108, compression element 107 tilts in sealed container 103 when the compressor tilts due to the influence of installation state and the like of the compressor. Thus, the relative positions of suction port 114 and opening 102 changes. Since coil spring 108 reduces the vibration of the compressor, the rigidity thereof is set low, and change in relative positions of suction port 114 and opening 102 is difficult to prevent.

As shown in FIG. 3, when suction port 114 is offset arranged in the rotating direction side of rotor 105 with respect to opening 102 of suction tube 101, the refrigerating performance rapidly lowers compared to the counter-rotating direction side.

Therefore, suction port 114 is arranged at outer wall surface 115 on sealed container side of suction muffler 113 in the first embodiment. In the projection view seen in the shaft center direction of opening 102, opening 102 and suction port 114 are arranged so as to be partially overlapped, and the opening area of opening 102 is made larger than the opening area of suction port 114. According to such configuration, suction port 114 is prevented from being largely offset arranged in the rotating direction side of rotor 105 with respect to opening 102 of suction tube 101 even when the compressor is installed in a slightly tilted manner. Furthermore, the low-temperature cooling medium that did not flow into suction port 114 cools outer wall surface 115 on the sealed container side of suction muffler 113, and cools the cooling medium in noise deadening space 112. Therefore, the cooling medium of low temperature is supplied to cylinder 111. In consequence, the refrigerating performance of the hermetic type compressor is stably enhanced regardless of the installing conditions.

In the present first embodiment, wall part 116 projecting from suction muffler 113 towards the inner surface of sealed container 103 is arranged in the rotating direction side of rotor 105 of suction port 114. Wall part 116 inhibits the flow of the cooling medium at the front of suction port 114, and delays the flow. Thus, the cooling medium of relatively low temperature remains at the front of suction port 114, and the rise in temperature of the cooling medium released into sealed container 103 from opening 102 becomes small. As a result, the cooling medium of low temperature is supplied to cylinder 111, and the refrigerating performance of the hermetic type compressor enhances.

The inverter is used as the electrically operated element in the present first embodiment, but an induction motor in which the rotation number of rotor 105 is constant speed may also be used. Similar effects are obtained with the induction motor by offset arranging suction port 114 with respect to opening 102 in accordance with the flow of the cooling medium at the front of suction port 114.

INDUSTRIAL APPLICABILITY

Therefore, the hermetic type compressor according to the present invention has high efficiency and reliability, and is applicable to the hermetic type compressor used in air conditioner, refrigerator-freezer device, and the like. 

1. A hermetic type compressor comprising: an electrically operated element accommodated in a sealed container and including a stator and a rotor; a compression element driven by the electrically operated element; and a suction tube communicating with an inside and an outside of the sealed container and including an opening that opens to the inside of the sealed container; wherein the compression element is elastically supported by a coil spring, and includes a shaft that rotates with the rotor, a cylinder forming a compression chamber, and a suction muffler forming a noise deadening space communicating with the cylinder; and a suction port linking the noise deadening space and a space in the sealed container to communicate with each other is formed in the suction muffler, the suction port being offset arranged in the rotating direction of the rotor with respect to the opening.
 2. The hermetic type compressor according to claim 1, wherein the opening and the suction port are arranged so as to at least partially overlap with each other in a projection view seen from the shaft center direction of the opening.
 3. The hermetic type compressor according to claim 1, further comprising a wall part projecting towards the inner surface of the sealed container in a rotating direction side of the rotor of the suction port.
 4. The hermetic type compressor according to claim 1, wherein an outer wall surface facing the inner surface of the sealed container is formed in the suction muffler; and the suction port is arranged on the outer wall surface of the suction muffler.
 5. The hermetic type compressor according to claim 1, wherein an opening area of the opening is greater than an opening area of the suction port. 